researching 4K acoustically transparent screens for my next home theater, I stumbled over "Hollywood Screens" (formerly "Image Screens"), located in Germany. They offer 4K AT screens with motorized masking for prices that seem relatively modest to me. Have a look at the following 2 videos, containing interviews with USA studio guys praising these screens for both their acoustic & video qualities:

Very interesting. I still think AT screens are a trade-off in terms of IQ. More so for 4K projectors as with 4K projectors you have to sit relatively close to the screen (to get advantage of high resolution) at which point screen texture might be an issue. Might be a good idea to contact them about getting a screen sample? Out of interest, what are their prices?

These are the German direct internet sale prices, though. Their homepage says that prices outside of Germany can be up to twice as high because in other coutries sales go the usual way through resellers etc.

Would love if somebody with experience could give these a try. I'm kinda scared buying something nobody on this forum knows...